Centrifugal pumping apparatus



f Jan. 29, 1929.

I. C. JENNINGS CENTRIFUGAL PUMPING- APPARATUS 8 Sheets-Sheet' 2 Filed March 18, 1926 bb A@ Jan., 29, 1929. 1,700,678

l. C. JENNINGS CENTRIFUGAL PUMP I NG APPARATU S Filed March 18, 1926 8 Sheets-SheetA 5' .a yf,

Jan'. 29, 1929. 1,700,678

' l. C. JENNINGS GENTRIFUGAL PUMPING APPARATUS.

Filed March 18, 1926 8 Sheets-Shee't' 4 `c. JENNINGS CENTRIFUGL' PUMPING APPARATUS Jan. 29, 1929.

Filed March 18, 1926 8 Sxvleecs-Sheet 5l Nm mm A@ INQN.

Jan.' 29, 1929.

l. C. JENNINGS CENTRIFUGL PUMPING APPARATUS 8 Sheets-Sheet e Filed March 18, 1926 l. C. JENNINGS CENTRIFUGAL PUMPING APPARATUS l `Ian. 29, 1929.

8 Sheets-Sheet' 8 Filed March 1 8, 1926 IWA Patented Jan. 2.9, 1929.

UNITED STATES PATIENT OFFICE.

IRVING C.I`JENNINGIS, F SOUTH NORWALK, CONNECTICUT.

CENTRIFUGAL IP'UMPING APPARATUS.

Application led March 18, 1926. A, Serial No. 95,737.

in different plants, and when assembled they frequently present' substantial variations in height and alignment.

It has been lconsidered very desirable to mount the pump directly upona rigid ex tension of the lmotor shaft, avoiding the-expense and complication of separate and ad# ditional bearings in theV pump casing. This combination has' been found unsatisfactory, however, on account of the necessity for very close and .accurate alignment of the motor and the Apump casing.

It is an important invention to provide a' construction by which a centrifugal pump and motor may be conveniently assembled and by which the necessity for extremely accurate alignment may be avoided.

, To the attainment of this object, I mount the impellerdirectly upon an extension of the motor shaft and I provide a stuiing box on the pump casing which may be slightly adt justed radially to provide 'for sli-ghtvariations in alignment between the motor bearings and the pump casing.

I also provide a oating or self-centeringr sealing devicein the pump casing for the wall opening in the impeller chamber into which the impeller: shaft extends. f

' ,By the lcombination of these' two devices, I provide a construction which' may b e easily and cheaply assembled without the necessity for extremely accurate alignment of the parts. This construction has been found very effective andreliable in operation.

As a feature' of this'construction, I'preferably provide a centrifugal pump in which 'the impellerV has a substantial radial' clearance in all parts ofits chamber and in which yielding so that'A it will adapt itself to slight object of my present l vthe packingof'the stuiiing box is sufficientlyl variations in the angular relation of the im peller shaft thereto.

A further object of my inventionis to (provide an air pump for priming purposes, rotatable in. its own se arate bearings on the pump casing, but driven by a self-aligning connectlon from the impeller shaft which is supported by the main bearings of the drivin motor.

y invention further relates to arrangements and combingtions of parts which will be hereinafter described and more particularly pointed out in the appended claims.

A preferred form of the invention and several modifications are shown in the drawings in which l Fig. 1 is a front elevation, partly in section, of a motor driven centrifugalpump of the double suction type and'adapted to Work under-a positive head;

Fig. l is a detail section of the extreme upper part of the pumpfcasing;

Fig. 1b is a detail sectionalvviw Ashowing the driving connection between the motor and pump;

Fig. 1c .is a detail section, taken along the line (1 -0 in Fig. 1";

Fi'g. 2 is a sectional front elevation of a double suction centrifugal pump,- designed for operation under a negative head and provided with a separate priming pump supported upon its own individual bearings and driven by the impeller shaft through la Selfaligning connection;

' Fig. Sis a sectional front elevation Vof a double suction centrifugal pump, having a I separate priming pump mounted directly upon Ian extension of the impeller shaft; Fig. 4 `is a sectional front elevation of a 'single suction centrifugal pump, `having a separate priming-pump mounted on individual bearings; u

' Fig. yfis a view similar to Fig. 3but show- .ing a single suction. pump;

Fi 6 is a view slmilar to Fig. 1 but showing a single suction pump;

' Fig. 6a is a 'detail section of the extreme p rtion of the pump casing; igs. 7, 8 and 9 are sectionalfront elevations of the different parts forming the casing pf a double suction centr'fugal pump;

Fig. 10 is a front elevation of the impeller for the same pump; and v v Figs. 11, 12 and 13 are enlarged sectional details of certain of the parts shown in Fig. 2. Referring particularly to Fig. 1, I4 have shown a motor driven centrifugal pump'of I ported in bearings 23 fixed in the motor frame 24. Only one bearing 23 is shown in Fig. 1 but it will be understood that a sec ond bearing will be provided at the left hand end of the' motor, as indicated at Fig. 6. Preferably one or both of' the bearings 23 will be in the form of a'thrust bearing adapted to limit end Aplay of the 'motor shaft25 in both directions.

The centrifugal pump P shown in mydrawings comprises a casing preferably formed in two parts which may be conveniently referred to as the volute or main casing member 26 and the cover member 27. An impeller chamber 28 is preferably formed i n tegral with the volute casing member 26 and a water space 29 is provided'between the left hand wall of the impeller chamber 28 and the left hand wall 30 of the pumpcasing. The cover member 27 is also provided with an innerwall 31 spaced from the outer cover 'and forming the right hand side of the impeller chamber. The space between the cover 27 and the inner wall 31 forms an additional water space 32 through which water may be ber 28.

A pet cock 29a (Figla) is provided to permit removal of airfrom the rwater Spaces.

The impeller `33 may be of a construction l common in such um s and its hub 33%l is mounted `upon an impe ler shaft 34 which in effect `forms an extension of the motor shaft 25. The impeller shaft 34 may be secured to the motor shaft in' any convenient manner but I prefer to use the construction indicated in Figs. l anda 1', in which a cylindrical recess 35 is formed in the end of the impeller shaft 34, to receive the outer end of the motor shaft 25.

The shaft 25 is freely slidable axially in the recess-35 but is provided with a key 36 which prevents relative angular movement of the pump shaft and the impeller shaft. A screw 37 is provided to hold the parts in the desired axial relation after assembly.

The impeller shaft 34 extends through an opening 40 (Fig. 1) in the left hand side wall `of the pump casingand is provided with a stuing box 41 having a soft annular packing 42 secured therein by a gland or retaining member 44. Any suitable means (not shown) may be provided for forcing the gland inward to compress the packing. A so-called lantern packing 45 may be inserted 4in the stniiing box as indicated in Fig. 1 and may be connected to `a water supply pipe 46 to provide a water seal for the stuffing box 41.

The stuffing box 41 is secured to the side wall 30 of the pump casing by bolts 47 passing through radial slots in the flange 48 of 'the stuliing box. The rinward extension 49 of the stuffing box is slightly smaller in diameter than the opening 40, so that the. stuffing box may be slightly adjusted radially and desired radial adjusttween the periphery of thek impeller hub and the inside of the opening 50; For this purpose, I provide a self-adjusting or self-centering sealing devicev comprising a ring 52 closely fitting-a cylindrical surface on the impeller hub and a second'rirg 53 fitting a re,-

cessor dpression 54 in the side wall of the impeller chamber. The rings 52 and 53 are freely slidable radially `relatively -to each other within a limited range vand are pressed yieldingly Aagainst 'each other by springs 55 mounted on studs 56, having their heads seated in the rings 52, said studs extending through 'slots in the openings or rings 53. In'

a double suction pump as shownin Fig. 1, a similar sealing device is also; preferably provided at the right hand'side' of the impeller.

By the construction above described, the manufacture and assembly ofaI motor driven centrifugal pump is very greatly simplified. v

The motor is assembled with the base 20 and is secured thereon bythe bolts 21. The pump casing is then placed on the base 20 and is moved axially to cause the shaft 25 to enter the recess 35, the 4stuffing box 41 being loosely securedto the pump casing during assembly.:

When the-parts are in the desiredA relation,

ne I

the screw 37 will be inserted to ix the axial relation, and the stuiingl box 41 'may then be secured in radially adjusted position on the .pump casing by the bolt-S47. If for anyl reason the motor shaft 25 should not be in exact alignment with the stuiing box 41, the

soft packing 42 will adapt'itself toy such slight 'angular divergencey between rthe shaft and the aposition assumed by the fmotor shaft 25 30 and impeller shaft 34, leaving the impeller prevented. The shelf-centering sealing devices will also adapt themselves to such very slight angular divergencelas may occur between the axis of the motor shaft and the axis of the impeller chamber;

/While somewhat similar 'sealing devices /and stuffing boxes may have been previously and separately employed for special purposes, Irderive very\ important mechanical and commercial advantages bycombinin in one structure a radially adjustable stung box forthe impeller shaft and a self-centering sealing device. for the impeller, as by this construction I- am able tol assemble separately-manufactured pump and motor units, without requiring unreasonable accuracy in the height orI alignment of the motor shaft and the pump casing.

In Fig. 2, I have shown a double centrifugal pump similar in its general construction to that shown in Fig. 1, but showing `also the provision of: an air pump for priming purposes. It is Well known that a centrifugal pump of the impeller type depends for its action upon the outward or centrifugal movement of 'Water in the impeller passages. If the water is all removed Vfrom the 4passages and the pump is' operating under a negative head, it is necessary to prime the pump before it will a ain start into voperation, as it has no li ting properties until water is supplied for the impeller passages. For such priming purposes, I have provided an air pump 60 mounted on the outer wall 61 of the pump' casing and connected to withdraw air from the water space 62 surroundingthe impeller chamber 63, thus caus-l ing 'water to flow into the water space 62 and fill the impeller passages, startmg the pump in operation.

I have indicated the pump 6() as being of the hydroturbine type shown in the lprior patent to Nash, No. 1,091,529 issued Mar.` 31, 1914, and comprising a rotor 64 mount-v ed on a shaft65 supported in. bearings 66 ,and 67 carried by a rigid frame extension 68 secured to the ump casing member 61.

The frame'mem er 68 is preferably provided with an /annularstorage lspace 69 in which a supply of make-up water for the air pump 64 maybe retained, the priming water owing tothe punp through suitable passages 70. AThis make-up ywater replaces any of the oppratin water of the'air pump which may e disc arged from the pump 'in the formof vapor or which maybe otherwise lost. .1

A driving member71 forms ing connection between the impeller shaft 72 andthe rotor shaft 65. The. end of .the impeller shaft is preferably threaded externally to receive a threaded nut 73 and has a self-alignrecess 74. The nut is held from rotation by a cross pin 77 and also acts as a binding nut for the impeller hub retaining it securely on its shaft.

At its opposite end, the driving member 71 is provided with a cross plate 78 loosely fitting a corresponding slotted recess in the body of the rotor 64 and transmitting 'rotary movement thereto. v

A sealing member 8() fits closely on the external surface of the shaft 72 and is pressed against a finished surface 81 on the inside of the pump casing wall, the sealing device be,- ing self-centering and the action being similar to that of the sealing rings previously described. l

The air pump thus constructed is a single self-contained unit which may be quickly and easily removed from the pump when desired and which rotates freely about. its own axi without requiring exact alignment with th axis of the impeller shaft 72 or exact posi+yu tioning axially relatively thereto. j In Fig. 3, L'I have shown a double centrifugal pump of the general type indicated in Figs. 1 and 2, butl designed for operation 'under a negative head. I have provideda priming pump 90 mounted on the cover plate 91'of the pump casing, with a rotor 92 supported directly upon an extension 93 of the 'impeller shaft 94. Ihave provided a sealling ring 95 for the impeller lshaft. or hub,

substantially as described with referencec to Fig. 2. I have also made special provislon for accurate axial or longltudinal adjustment of the rotor 92 on the impeller shaft extension 93, such adjustment being rendered necessary in order that the rotor may be'axi-A ally positioned accurately within the air pump chamber.

For-this purpose, I provide screw threads upon the end portion of the shaft extension .93, said threads fitting the inside of a double threaded sleeve 96. The outside ofthe sleeve is threaded to t a threaded recess 97 in the body'of therotor 92. The internal and ex, ternalv threads of the sleeve 96 are preferably of the same hand but of different pitches,'so

that a veryne diiferentialaxial adjustment f semi No. 101,827,11ed April 13, 1926.

lThe combination of the radially adjustable stutlingbox 41,the self-centering1 sealing members for the impeller hub, and t e sealing ring 45 for the exteirion f the impeller shaft tol the air pump permit th otating parts of the.I

' centrifugal pump and of the air pump to align themselves'with the motor shaft, and do away with the necessity for extremely close and accurate alignment of these separate units.

In Fig. 4, the construction is substantially similar to that previously described, except that'the centrifugal pump is of the single suction type for negative head. The air pump is supported as in Fig. 2 upon its own individual bearings and is flexibly connected with the end of the impeller shaft.

In Fig. 5, the construction is similar in a general way to that shown in Fig. 3, with the exception that the centrifugal pump is of the single suction type and an extra storage space 100 is provided for priming water for theair pump'lOl.

In Fig. 6, I have shown my improvements as applied toA a single suction centrifugal pump designed tov operate under'a positiye head and thus requiring no priming air pump for its operation.

Having thus described my invention as applied to several different combinations of centrifugal pumping apparatus and having fully pointed out the important advantages derived from` the combination of elements herein described, it is believed that furthel` and additional description of the operation wilf not be found necessary.

Furthermore, I do not Wish to be limited to the details herein disclosed otherwise than as set forthin the claims, but What-I claim 1s:-

1. In a centrifugal pumping apparatus,a base, a driving member rotatably mounted in fixed bearings on said base, a centrifugal. pump having a casing fixed relative to said driving member bearings and forming anV impeller chamber, an impeller supporting member forming a rigid extension of said driving member and extended through an opening in one Wall of said chamber to the interior thereof, a stuffing box for said impeller supporting member mounted for slight radial adjustment on said pump casing, and a self-centering sealing device effective to seal the opening in the wall of said im- I peller chamber around said impeller supporting member. p 4 I A 2. The combination ina centrifugal pumping apparatus as set forth in claim 1, in which the stuffing box is provided With a yielding said casing opening.

said member to find its own center relative-to 4. In a centrifugal pumping apparatus,

al base, a driving membcrrotatablg7 mounted in fixed bearings on said base, al centrifugal] pump having a casing fixed relative to said driving member bearings and forming an impeller chamber, an impeller for said pump rotatable in said chamber, an impeller sup orting member forming a rigid extension o said driving member and extended through anl opening in one wall of said chamber to the interior thereof', a stuffing box for said impeller supporting member mounted for slight radial adjustment on vsaid pump casing, and

a self-centering sealing device having a portion floating with said impeller supporting member and effective to seal the opening in the Wall of said chamber around said impeller Supporting member.

5. In a centrifugal pumping apparatus, a base, a motor having a rotating driving shaft, a motor casing fixed to said base and having fixed bearings -for said shaft, a centrifugal pump having a casing fixed to said base and having' an impeller chamber with an opening in one side Wall substantially aligned withl said driving sha-ft, an impeller rotatable in said chamber but having substantial radial clearance at all parts thereof, an impeller .supporting member forming with said driving shaft a rigid rotatablelmember extending into said pump casing and through said Wall opening into the impeller chamber, a. stuffing-box for said rotatable member mounted on said pump casing, securing means for said stuffing box permitting slight radial adjustment thereof on said casing, and a selfcentering sealing device effective to seal the Wall opening around said impeller supporting member.

6. In a centrifugal pumping apparat-us, a

motor having a rotating driving shaft, a a

motor casing having fixed bearings for said shaft, a centrifugal pump having a casing fixed relative to said motor 'casing and having an impeller chamber with anA opening in one side Wall substantially aligned with said driving shaft, an impeller rotatable in said chamber and having substantial'radial and axial clearance at all parts thereof, an impeller supporting member forming With said driving shaft a rigid rotatable member extending into said pump casing and through said lWall opening into the impeller chamber, a stuffing box for said rotatable member mounted on said pump casmg, and a sealing ring surrounding said impeller supporting member at saidl wall opening and radially self-adjusting relative to a second -sealing member supported by said chamber side wall.

7. In a centrifugal pump-ingapparatus, in combination, a vcentrifugal pump having a casing with an impeller chamber therein, an impeller for said pump mounted in said -chamber on a rigid rotatable driving member extending within said chamber, means to support and rotate said'driving member in fixed bea-rings, said supporting and rotating meansbeing. external to and separate from said pump and casing `and determining the axis of rota-tion of said impeller, said impeller having substantial radial clearance in said impeller chamber, a stung box for said rotating driving member on said pump casing, adjustable radially for alignment with said driving member, means to secure said s tuling box to said pump casing in adjusted position,

and a self-centering sealing device edectiveI to prevent leakage from said impeller chamber around said driving member.

8. The combination in a centrifugal pumping apparatus as set forth in claim 7 in which said stuffing box has a slightly yielding packing permitting a slight variation in angular alignment of said driving member with said casing and stuffing box.

9. The combination in a centrifugal pumping apparatus as set forth in claim 7, in which said stuliing box has a slightly yielding packing permitting a slight variation in angular alignment of said driving member with said casing and stuiiing box, and in which 'said sealing device also permits a similar slight variation in angular alignment of said impeller shaft relative to said im'peller casing without attendant leakage.

10. In a centrifugalpum-ping apparatus,

in combination, a centrifugal pump having a casing with an impeller chamber therein, an impeller for said pump mounted in said chamber on a rigid rotatable driving member extending within said chamber, means to support and rotate said driving member in fixed bearings, said supporting and rotating means being external to and separate from said pump and casing and determining the axis of rotation of said impeller, a radially adjustable stuffing box for- Said driving mem-4 ber mounted 0n said pump casing, a selfcentering sealing device for said driving member in said impeller chamber, a priming air pump'having a casing mounted insubstantial alignment with saidimpeller chamber, a rotor in said air pump mounted in balgrings fixed insaid air pump casing, and a se f-aligning driving` connection between.

said rotor and the driving member of said centrifugal pump.'

11. a centrifugal umping apparatus, in com ination, a centri ugal pump having a casing with anhimpeller chamber therein, an

impeller for said pump mounted in said chamber on a rigid rotatable driving member extending within said chamber, means to adjustable stufiing box for said driving member mounted on said pump casing, a selfcentering sealing device for said driving member in said impeller chamber, a priming air pump having a casing mounted in substantial alignment with said impeller chamber, a rotor in said air pump mounted in bearings fixed in said air pump casing, a driving connection between said rotor and the driving member of said centrifugal pump permitting slight variations in alignment between said rotor and said driving member, and a self-centering sealing device for said driving member between said centrifugal pump and saidl air pump. j

12. A centrifugal pumping apparatus comprising a base, a motor having a frame mounted on said base, a centrifugal pump having a casing separately and rigidly mounted on said base, said casing having a separate impeller chamber enclosed thereby and mounted in fixed relation thereto 7but having side walls substantially spaced therefrom, a motor shaft rotatable in fixed bearings in said motor frame, an impeller rotatable in said impeller chamber but rigidly secured to an extension of said motor shaft andl ing and for said shaft extension in one of .said impeller chamber walls, said sealing means being adaptable to variations in both the axial and radial position and alignment of said shaft relative to said pump" casing and of said extension relative to said impeller chamber.

13. The combination in a centrifugal pumping apparatus as set forth in' claim 12, in which a priming air pump is provided havingA a rotor rotatable in bearings fixed relatively to Saidbentrifugal pump casing, and in which a self-aligning driving connection is provided between said rotor and said shaft extension, and in which an additional floating sealing device is provided for the driving connections between said air pump and sald centrifugal pump, positioned at the outer wall o f the centrifugal pump casing.

14. In a centrifugal pumping apparatus, a base, a motor having a rotating driving shaft, a motor casing mounted on said base and having fixed bearings for said shaft,a centrifugal pump having a casing mounted infixed an impeller chamber with an opening in one side wall substantially aligned with said driving shaft, an impeller rotatable in said relation to said motor casing and having chamber, an impeller supporting member forming with lsaid driving shaft a rigid rotatable member extending into said pump casing and throu h said wall opening into 5 the impelleroham r,

rotatable member mounted on saidpump casing, securing means for said' box permitting a stalling box for said slight radial adjustment thereof on said casing and a self-centering sealing/device effective to seal said :wallopening around said impeller supporting member.

In testimony whereof I have hereunto afxjed my signature.

t IRVING C. JENNINGS. 

